Setting Sages Questioning

Wild’s Triplet, Arp 248. Image is 30′ x 30′. Courtesy POSS-II.

[Note: this entry has been edited to include the second observation, which was inexplicably left out in the previous version.]

Two more observations before surgery; two more before unusually-relentless rains wiped out May and part of June.

April had already proven difficult, weather-wise. Where we usually had several days of clear Moonless skies during the month, we’d only had one day early in the month, and now only two toward the end. With a week before I had my foot cut open and three months of rehab afterward, I had no hesitation getting out when a halfway-decent forecast finally presented itself. Nor did most of the others, really—having been cooped up by the rain, the Irregulars were champing at the bit. And so we made the 45-minute pilgrimage out west toward the sandstone Linslaw crag, in pursuit of individual agendas but a singular goal: the capture of ancient starlight.

With the 20-inch Obsession and new ladder in tow, and galaxy season well underway, it was time for another round of chasing down flat galaxies. By the time I was healed up, it would be time for the flat galaxies of autumn, of which I had barely scratched the surface.

As darkness overtook daylight, our first actual target for the night was SN2022hrs, the brilliant supernova in NGC 4647 (the companion galaxy to Messier 60). This was one of the brightest extragalactic supernovae I’d ever observed, reaching better than 12th magnitude in our estimation [although officially only 12.3 at its peak]. EAS members would end up tracking this supernova all the way into July. Five scopes lingered on the supernova; Robert even viewed it in his 50mm binocular scope (“Magic”).

Two hours after sunset, it was time for note-taking and more-structured observing. I started with an object that I had previously seen from Eureka Ridge in the 12.5-inch scope, but which really deserved notes made through the Obsession.

MOON: 23 days (rose at 3:15 AM; 46% illuminated)

SQM: 21.60
NELM: not checked
WEATHER CONDITIONS: temps to low 40s; humid with slight dew; air still; chilly
All observations: 20″ f/5 Obsession Dob, 14mm ES 82˚ eyepiece (181x, 0.45˚ TFOV) or 7mm TeleVue Nagler (363x, 0.21˚ TFOV) unless otherwise noted

NGC 3044 (Sex): First for the night—probably the last night until September—is NGC 3044 in Sextans. I’ve seen this one before; I first got it in the 12.5-inch scope and made a note to come back to it because I was so impressed with it then. This is a huge, very underrated edge-on/flat galaxy, elongated 100° PA. It’s an irregularly-bright galaxy with no central brightening (or widening, for that matter), and there’s no real hint of a nucleus here. The galaxy is not razor thin; it’s 4.25’ x 0.4’. It seems as if the SF end is the brighter end; both of the ends fade out gradually, but the NP end is stretched out a little longer and more diffusely than the SF. 1’ N of the NP end of the galaxy is a 14.5-magnitude star. 6’ NP the galaxy is a 12th-magnitude star with a 13.5-magnitude star S of it by 0.5’. P somewhat N of the galaxy by 8’ is an 11.5-magnitude star; 3’ SF the galaxy is a 13th-magnitude star that has another 13th-magnitude star S of it by 2’. The brightest star in the field is 15’ N very slightly F the galaxy and is 10th magnitude; it has a 14th-magnitude star P very very slightly N of it by 0.5’. In the 7mm Nagler: the galaxy is huge at this magnification; there’s still no real nucleus or core visible. But it seems like on the NP end there’s a detached segment that’s very slightly brighter than the rest of it—I mentioned that it was irregularly bright, and that’s really coming out here. It’s hard to get a good read on that detached bit beyond its presence there. This is certainly one of the better objects in the Flat Galaxy Catalogue.

Loren had built a riser for his 18-inch Obsession, the better to track down horizon-scraping planetary nebulae like NGC 3132 and NGC 2818. He was unsatisfied with it on the evening, though, and while observing NGC 3044, I stopped to help him and the others lift his scope down from the riser. (It was quite a team effort, judging by the conversation in my audio notes.) Apparently, Dan had been observing the Draco Trio at the time, as I warned him about the “false trio” that I’d stumbled across several years before.

But back to the task at hand, with a galaxy significantly more difficult than the previous. (And speaking of hands, I’d already gone to my electric gloves for warmth; the evening was already well into the “hibernation” range of temperatures.)

UGCA 221 (MCG-3-28-15; Hya): A really difficult one here, UGCA 221 in Hydra, down near Alkes (Alpha Crateris). This galaxy is very wraithlike and difficult but pretty immediately noticeable when swept into the field; the eye definitely says there’s something there, even though it’s very difficult to detect and hold. It’s 2.0’ by 0.25’, with almost no real identifiable characteristics to it at all. Averted vision doesn’t really help it that much— actually, it’s almost as difficult in averted vision as it is in direct. I’m gonna say it’s 160˚ PA, but I’m certainly not gonna hold to it; it’s so faint you could probably convince me it was 90˚ if you wanted to. At moments, it seems like the S end is more diffuse than the N, although everything about this is diffuse and poorly defined. (You’d think a flat galaxy would be fairly well defined, but not this one.) It really is just kind of a glow. There are some vaguely noteworthy stars in the field, but the galaxy is so faint it’s even hard to get distances from it: 5’ due P the galaxy is the N-most of a pair, angled NP-SF to each other and separated by 0.67’; those are both 12th magnitude, with the one to the NP somewhat brighter than the other… maybe 12 and 12.5 magnitude. Due N of the galaxy by 2.75’ is the SP star in an arc of three; that star is 12.5 magnitude and has a 13.5-magnitude star 2’ F very very slightly N of it, and that star has an 11.5-magnitude star NF it by 2.5’. The brightest star in the field is 13’ SP the galaxy and is 8.5 magnitude. So let’s throw the 7mm on this one and see if anything improves; as we saw from NGC 3044, just adding the magnification doesn’t necessarily mean anything.
 At this magnification, there still isn’t much to the galaxy: no core, no nucleus, no strip of central brightening… just a really weak wraith of a galaxy. I wish I had more to say about it, but there’s just not that much there. 

I’d been planning for several Springs to return to Wild’s Triplet with heavier artillery, having first (and unexpectedly) seen this trio at Eureka with the 12.5-inch several years before. Since then, I’d forgotten about it, or put it on the back burner, or only thought of it when I had the 12-5-inch out. But the topic had reappeared on CloudyNights, and so I made sure to add it as a break from the flat galaxies in my agenda. And here it was:

PGCs 36733, 36723,36742 (Wild’s Triplet; Arp 248 [Vir]): After several years of forgetting about it and not going back to it, this is Wild’s Triplet. Once again, I’m impressed with how bright the “main two” of these galaxies are; the third one is very difficult. But I could see all of them in my 12.5-inch scope, one of the most-difficult things I’ve ever seen in that scope, and from Eureka Ridge no less. But here, the two more S galaxies are unmistakable; I’m really surprised at how easy they are (the third one is just a real bugger tonight), but it’s the second one from P [OK, that was a good momentary look at the third one], the largest one of the group, [PGC 36733], that’s the most obvious of the three. In the 14mm, it’s 0.5’ in diameter, with a distinctly obvious core and every now and then what looks like just the faintest flash of a nucleus. Even in averted, though, it doesn’t steady up. The galaxy’s not smoothly round; it’s kind of irregular-shaped overall, even if the overall effect is roughly round. (This magnification probably isn’t the best to use; this might be one for the Delos.) The P-most of the three galaxies [PGC 36723] is second in brightness, and it’s not particularly bright; the first one I noted is really bright relatively for what it is; this second one is much more diffuse, 0.5′ x 0.3′, and elongated somewhat P-F; it’s P very slightly S of the brightest one by 2.5’. It’s much more diffuse, much less defined, but does have a smallish brighter core to it; I know these three are all interacting, but I wonder if it’s being pulled in the direction of the other one and that’s the cause of the visual distortion. For a second, [36733] seemed to have a tiny sliver extending from the S edge of the core toward the F; this was more than illusory, it was almost certainly there. The third galaxy [PGC 36742] is very much an occasional averted vision flash about 1.75’ N slightly F [36733]. But I can’t do anything to get a good visual fix on it; it’s just a tiny faint spot. It may have a nucleus, though, which is what I’m picking up every so often. From [36733] N very very slightly P by 6.5’ is a 7.5-magnitude star that is a huge unavoidable distraction from the galaxies, and that star is the P-most vertex of a little isosceles triangle; the other two stars are F slightly S of it by 2.25’; the third one is 1’ S very slightly P that one (the second vertex that I mentioned is 14th magnitude, and the third vertex is 13.5 magnitude). 5.25’ S very very slightly P [36733] is an 11.5-magnitude star. So I’m going to go ahead and change eyepieces and see if I can pick that third one out a little bit better. There’s definitely a stellar nucleus to [36733].  The third [36742] is very slightly N-S elongated, but very small, and that was a nucleus that I was seeing in that one too; I know I saw that in the 12.5-inch, but I’m surprised as hell as to how. This is too much power for it. [36742] is super diffuse other than that nucleus, and might be 0.25’ x 0.125’. There’s another glimpse of a possible spiral arm or whatever off [36733]; it definitely seems to extend from the N to the P, which is the opposite direction from the earlier sighting I had of such an extension. That galaxy also seems to be extended P from the nucleus; or, rather, the nucleus is not centered in it. It’s good to revisit this group after several years with both more experience and larger aperture.

I suspect it won’t be long before I return to Wild’s Triplet yet again—a fascinating group.

One of my heated gloves had died; I had to switch it out for an unheated one with a chemical handwarmer in it. But to hell with inconvenience; this was SCIENCE.

NGC 4703; PGC 43343 (Vir): One that’s not as impressive in the eyepiece as it is in photographs: NGC 4703 in Virgo, P and N of Spica, and it is not as easy as one might expect from an NGC. (I know that generalizations like that aren’t scientific.) This one is surprisingly long in averted vision; in averted, it’s about 2.75’ x 0.3’ at the middle, and is elongated in PA 160˚. There is definitely a core there, a central bulge; it has obvious central brightening and central enlargement to it, and the overall appearance is clearly irregularly bright. The spiral arms just peter out completely—that’s why averted vision is so important on galaxies like this; without averted, this is only about 1.5’ long. S somewhat P the galaxy by 8’ is a 7.5-magnitude star; S of the galaxy by 6.5’ is a 12.5-magnitude star, and then further S of the galaxy, 10’ S, is an 11.5-magnitude star that has S very very slightly F it a diffuse little galaxy [PGC 43343] with a small, slightly brighter core to it and a very, very diffuse halo; that galaxy is no more than 0.75’ around. There may be a substellar nucleus, but it’s intermittent at best. In the 7mm, 4703 also seems to have a nucleus, a very faint stellar one. The arms definitely need less in the way of averted vision to see at this magnification, and that central region, the brighter central region, is much more obvious. That’s a really fine galaxy; I don’t have much more to say about it at 7mm, but the extra magnification really helped on this one, and it’s definitely got a good presence to it.

I noticed, while taking notes on NGC 4703, that Scorpius had risen; Antares flickered in multi-colored splendor through the haze circling low around the horizon. (The changing colors of a star low to the horizon meant that there was considerable turbulence to the atmosphere—not uncommon along the horizons at Linslaw, due to its proximity to the Pacific Ocean.) Would I even get to observe Scorpius again this summer? Several bright Lyrid meteors added to the evening spectacle throughout; I even saw a few of them.

Meanwhile, Robert was packing up to leave. I suspected most of us would be following fairly soon; four-plus hours after sunset, the chill in the air was substantial. For me, I’d been awake since 5 AM, having put in a full day at the factory. My caveman brain was going a million miles per minute, but I had to admit that the shambling corpse it was housed in was pretty run down already.

Robert left while I was taking notes on my last object for the night. This was more noteworthy than it seemed—the crag had space for six vehicles at most, and then only if parking and telescope setup allowed for that many vehicles to pass. I usually parked at the far end, setting up my scope on the eastern-most flat space in the observing area; this time, I was closer to the western edge, near the road up/down the crag. This meant that Robert had to negotiate his car between my scope and Dan’s, as well as Loren’s truck. The resultant maneuvering required headlights, which required covering our heads to preserve dark adaptation (for those of us still observing; Loren guided Robert through). It took several minutes, but he eventually made it, with Loren soon after him. During the course of Robert’s departure, I added a friendly “drive careful,” which drew snickers from the others; I warned them not to taunt the group linguist on his grammar (the words that I used were, quote, “I will roast somebody’s ass.”).

Meanwhile, my final galaxy for several months continually called me back to the eyepiece.

NGC 5073 (Vir): Another from the 160-170˚ PA club tonight, this is NGC 5073 in Virgo, and it’s a long, fairly-bright-as-such-things-go streak, maybe 3.0’ x 0.3’. It’s actually a really well-defined galaxy; there’s no real sense that there’s more to it that’s visible in averted vision or anything like that. This is a good example of how the visible profile of a flat galaxy creates a different expectation than that of a face-on spiral—even though it’s an NGC, you think it should be brighter than it is; it’s still certainly readily apparent, but not as it would be if it was more inclined, with the core visible. I’m gonna just average it and say it’s about 165˚ PA, with even illumination all the way along the major axis. This is one of the few that I’ve done where you can actually see the taper in the spiral arms to its full extent.  N very slightly P the galaxy by 6.5’ is a 9th-magnitude star that has a 14th-magnitude star SF it by 1’, and then 0.5’ P slightly S of the 9th-magnitude star is a 15th-magnitude star. Then from the galaxy N slightly P by 3.75’ is a 15th-magnitude star, and from the galaxy P somewhat S by 5’ is a 12th-magnitude star with a 14.5-magnitude star 10” N slightly F it. 9’ S very very slightly P the galaxy is the N-most of a pair, which has S very very slightly F it by 0.75’ the second and brighter star; those are 13th and 12th magnitude. The brightest star in the field is P somewhat S of this one by 14’, just on the edge of the field, and is 8.5 magnitude.
With the 7mm Nagler, I’m seeing a fair amount of irregularity to the surface brightness here, but again, it’s just a really well-defined object—there’s still no sense that there’s anything beyond the directly visible extent of it. There may be, in the galaxy’s N end, a very, very faint embedded star, just above threshold level. I’m actually suspecting a quasi-stellar nucleus in averted vision (despite talking about how everything with this one is apparent in direct). This is a really beautiful and classic, though not overly bright, flat galaxy.

Dan and I joked about my not using my 10mm Delos, which he refers to as “the Precious.” I was back to fearing for the eyepiece’s safety, and made it a Spinal Tap reference, in which Nigel tells Marty not to touch or even look at one of his guitars.

I drove home after a final, lingering look around the site. A lot could happen in the three months I was going to be laid up—what if, for some reason, I never made it to Linslaw again? We had fair warning that Eureka Ridge was going to be gated off, but what if someone gated off the road to Linslaw? What if the gun worshippers or the forest squatters made it unsafe or unusable? This was the best observing site I’d ever had. It felt like sacred ground.

Despite my self-assurances, the drive home seemed like a finality.

II. We had one more observation before the month closed and my foot got opened up and the unseasonal rains came.

The lot of us convened at the Oxbow that next night, as it was the site of best forecast—and a fairly middling one, at that. We could tell the transparency was mediocre, even in daylight; a literal purple haze colored the southern reaches of the sky, and there was a “softness” to the sky behind the rocky hills in every direction. Still, this was a final swing at celestial glory for a considerable while, and none of us was willing to pass it up. (Prescient for the others, given the amount of rain that was to come.)

There were three 20-inch scopes, an 18-inch scope, and Robert’s binoscopes arrayed in the observing area, all of them making use of the better conditions early; things were predicted to get worse sky-wise as the night progressed.

MOON: 22 days (rose at 3:15 AM; 48% illuminated)
SQM: 21.2
NELM: not checked
WEATHER CONDITIONS: temps to upper 40s; slight dew; slight breeze, hazy; chilly
All observations: 20″ f/5 Obsession Dob, 14mm ES 82˚ eyepiece (181x, 0.45˚ TFOV) or 7mm TeleVue Nagler (363x, 0.21˚ TFOV) unless otherwise noted

While waiting for it to get fully dark, and hoping the transparency would be good enough for me to examine a few more flat galaxies, I stopped in on some of the familiar spring showpieces. Hickson 44, in Leo’s mane, was the most impressive I’d ever seen it; even the fourth galaxy, faint NGC 3187, stood out clearly from the background, and nearby NGC 3190 showed the barest hint of a dust lane. This was astounding—in such mediocre transparency, fine details and dim objects were still well within our grasp.

I continued on: NGC 2903, the Leo Trio, the Antennae Galaxies (accidentally sweeping up NGC 4027, a distorted one-armed spiral, along the way; I’d already taken notes on this one with the 12.5-inch), and the Sombrero (M104). But as I observed these galaxies, I could tell that we were already losing the already-tenuous transparency.

I started on my list for the night, but it was already too late. Each of the flat galaxies I’d made note to explore was fainter than the one before it. These were already difficult objects to observe; decaying sky conditions made them—if not impossible to take notes on—then certainly so diminished that it wouldn’t be “fair” to take notes on them now. I’m sure I dropped a few epithets off the ladder as my chances of taking notes came to an end for the season.

What to do when the big scope is set up and the faint stuff just can’t cut through the haze? Look at brighter stuff. The seeing was still decent, at least, so I simply went back to the first object class to have captured my attention: globular clusters. Spring isn’t prime time for globulars, but enough of them were visible to make the rest of the evening worthwhile: the M53/NGC 5053 pairing, NGC 5466 in Boötes, M3, NGC 5634 in Virgo, NGC 5694 in Hydra (an object of great nostalgia for me, as it was the most-difficult object I’d seen with my 8″ SCT in Cincinnati, and I was proud of the observation), M5 in Serpens, and M107 in Ophiuchus. I would’ve ended with M13, but it was still thoroughly buried in the light-dome of Eugene (which was worse than usual because of the reflecting haze).

But the transparency continued to dwindle, to the point that even the globulars were visibly diminished. We yielded, as a group, to the failing sky.

I packed up more slowly than usual and was last one out for the tricky drive home.

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